content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  package io.reactivex.common.internal.functions;
  
  import io.reactivex.common.functions.BiPredicate;
  
  /**
   * Utility methods containing the backport of Java 7's Objects utility class.
   * <p>Named as such to avoid clash with java.util.Objects.
   */
  public final class ObjectHelper {
  
      /** Utility class. */
      private ObjectHelper() {
          throw new IllegalStateException("No instances!");
      }
  
      /**
       * Verifies if the object is not null and returns it or throws a NullPointerException
       * with the given message.
       * @param <T> the value type
       * @param object the object to verify
       * @param message the message to use with the NullPointerException
       * @return the object itself
       * @throws NullPointerException if object is null
       */
      public static <T> T requireNonNull(T object, String message) {
          if (object == null) {
              throw new NullPointerException(message);
          }
          return object;
      }
  
      /**
       * Compares two potentially null objects with each other using Object.equals.
       * @param o1 the first object
       * @param o2 the second object
       * @return the comparison result
       */
      public static boolean equals(Object o1, Object o2) { // NOPMD
          return o1 == o2 || (o1 != null && o1.equals(o2));
      }
  
      /**
       * Returns the hashCode of a non-null object or zero for a null object.
       * @param o the object to get the hashCode for.
       * @return the hashCode
       */
      public static int hashCode(Object o) {
          return o != null ? o.hashCode() : 0;
      }
  
      /**
       * Compares two integer values similar to Integer.compare.
       * @param v1 the first value
       * @param v2 the second value
       * @return the comparison result
       */
      public static int compare(int v1, int v2) {
          return v1 < v2 ? -1 : (v1 > v2 ? 1 : 0);
      }
  
      /**
       * Compares two integer values similar to Long.compare.
       * @param v1 the first value
       * @param v2 the second value
       * @return the comparison result
       */
      public static int compare(long v1, long v2) {
          return v1 < v2 ? -1 : (v1 > v2 ? 1 : 0);
      }
  
      static final BiPredicate<Object, Object> EQUALS = new BiObjectPredicate();
  
      /**
       * Returns a BiPredicate that compares its parameters via Objects.equals().
       * @param <T> the value type
       * @return the bi-predicate instance
       */
      @SuppressWarnings("unchecked")
      public static <T> BiPredicate<T, T> equalsPredicate() {
          return (BiPredicate<T, T>)EQUALS;
      }
  
      /**
       * Validate that the given value is positive or report an IllegalArgumentException with
       * the parameter name.
       * @param value the value to validate
       * @param paramName the parameter name of the value
       * @return value
       * @throws IllegalArgumentException if bufferSize &lt;= 0
       */
      public static int verifyPositive(int value, String paramName) {
          if (value <= 0) {
              throw new IllegalArgumentException(paramName + " > 0 required but it was " + value);
          }
          return value;
      }
  
      /**
       * Validate that the given value is positive or report an IllegalArgumentException with
       * the parameter name.
       * @param value the value to validate
       * @param paramName the parameter name of the value
       * @return value
       * @throws IllegalArgumentException if bufferSize &lt;= 0
       */
      public static long verifyPositive(long value, String paramName) {
          if (value <= 0L) {
              throw new IllegalArgumentException(paramName + " > 0 required but it was " + value);
          }
          return value;
      }
  
      static final class BiObjectPredicate implements BiPredicate<Object, Object> {
          @Override
          public boolean test(Object o1, Object o2) {
              return ObjectHelper.equals(o1, o2);
          }
      }
  }
  